Actually implement wrapInTransaction, through it will still throw

src/InMemoryEntityManager.php

@@ -29,6 +29,7 @@
     Driver\MappingDriver,
 };
 use RuntimeException;
+use Throwable;
 
 use function class_exists;
 
@@ -305,6 +306,28 @@ public function beginTransaction(): void
         throw new RuntimeException(__METHOD__ . ' not yet implemented');
     }
 
+    /**
+     * @inheritDoc
+     */
+    public function wrapInTransaction(callable $func): mixed
+    {
+        $this->beginTransaction();
+
+        try {
+            $return = $func($this);
+
+            $this->flush();
+            $this->commit();
+
+            return $return;
+        } catch (Throwable $e) {
+            $this->close();
+            $this->rollback();
+
+            throw $e;
+        }
+    }
+
     /**
      * Commits a transaction on the underlying database connection.
      */
@@ -480,9 +503,4 @@ private static function getDefaultMappingDriver(): MappingDriver
         }
         return self::$defaultMappingDriver;
     }
-
-    public function wrapInTransaction(callable $func): mixed
-    {
-        throw new RuntimeException(__METHOD__ . ' not yet implemented');
-    }
 }